This pilot study will investigate the feasibility of conducting an intervention trial of micronutrients for the prevention of lung cancer among tin miners in Yunnan, China. The pilot will specifically be looking at general study logistics, ability to identify and recruit miners at high risk, adherence to pill taking, potential adverse effects from intervention agents, quality control for data and sample collection/analysis, and baseline nutritional status among the miners. Lung cancer rates are extraordinarily high among these miners. Males more or less than 40 years old with underground mining experience have a crude annual incidence of 1240 x 10-5 while miners aged 60-64 have an incidence rate in excess of 2500 x 10-5 annually. While the reasons for these high rates are not completely known, the miners have been exposed to a number of known carcinogens, including tobacco smoke, radon and radon daughters, and arsenic. In addition, dietary intake of several micronutrients are thought to be inadequate. This study is being conducted by the Cancer Prevention Studies Branch in collaboration with the Department of Epidemiology of the Cancer Institute of the Chinese Academy of Medical Sciences, the Labor Protection Institute of the Yunnan Tin Corporation, and the Surveillance and Operations Research Branch.